11/11/2025
San Francisco is famous for its distinctly tangy sourdough but... how did it start?
Deeply inspired by the nascent French bakers of the California Gold Rush (1848 - 1855), I created a recipe to reflect their hardships, skills, and resourcefulness: a rustic, tangy sourdough featuring freshly stone-milled Heirloom White Sonora Wheat, Heirloom Club Wheat, Heirloom Blue Corn, Heirloom Gazelle Rye, with French-Style "Type 80" Hard Red Spring Wheat Flour.
French Bakers of the California Gold Rush in 1849
On January 24, 1848, gold was discovered at Sutter's Mill in Coloma, California. News spread around the world and then, in 1849 alone, approximately 90,000 American and foreign migrants (nicknamed "forty-niners") flooded into California. Thousands of these forty-niners arrived from France by ship, some of whom were skilled bread bakers. Rather than mine for gold, they chose to bake in boomtowns, most notably San Francisco and French mining towns in Sacramento Valley.
Flour Shortage
In the initial years of the Gold Rush, California imported significant amounts of wheat, primarily from Oregon (USA) and Chile in South America. Key factors for California's mass imports of wheat were: explosive population growth, severe labor shortage (e.g., farmers abandoning their fields to search for gold), lack of infrastructure to produce and transport supplies, and inflated prices for food staples.
Brief History of Each Grain (in context of the California Gold Rush in 1849)
🌾 White Sonora Wheat
When the Gold Rush began, California wasn't as agriculturally developed as Oregon where settlers had been growing wheat in the Willamette Valley for decades prior. Prompted by the demand in California, in 1849, about fifty ships entered the Willamette River to purchase grains and lumber at any price. Merchants subsequently shipped goods downriver from Portland to the Pacific and on to San Francisco.
Most of Oregon's flour exports to California during the Gold Rush consisted of simple, unbranded, and unstandardized flour. The flour was likely produced from a class of soft white winter wheat called "White Lammas," introduced to the Pacific Northwest in the 1820s by the Hudson's Bay Company (HBC). Among the White Lammas-class heirloom wheats in the US, White Sonora is the most widely documented and commercially available variety.
🌾 Club Wheat
In the early years of the California Gold Rush, Chile was the only significant source of wheat on the Pacific Rim. The shipping route between Chile and San Francisco was already well-established, part of a Pacific coastal trade network that had been operating since the 1830s. In 1849, Chile exported 8,700 tons of grain, along with 6,900 tons of flour, to California. It's unclear how much of the grain was specifically wheat. Nonetheless, the Chilean club wheat became highly valued and fed the Gold Rush population in California.
🌽 Corn and Rye
Supply shortages were extremely frequent during the California Gold Rush, especially in the early years. Flour was often imported and expensive. In towns like San Francisco, merchants made fortunes by "mining the miners," selling food staples at massively inflated prices due to high demand and limited supply. Before the Gold Rush, the price for a pound of flour in California was about 1.5 cents. Following the start of the Gold Rush in 1848, the price soared to as high as $1.50 per pound, the equivalent of $63 per pound in today's dollars.
Overcoming these hardships, both French and other bakers would use a mix of imported flour and locally milled grains (such as corn and rye) to produce what they could.
🌾 Type 80 Wheat Flour (imitating 1800s bolted flour)
Wheat flour was "bolted" (sifted) in the US from the colonial era to the 1860s to produce a refined, whiter flour. To produce bolted flour, milled grain would pass through a "bolting cloth"—a fine mesh sieve made of materials like silk or wire. The result was a high-extraction flour, typically retaining between 75% and 85% of the original grain. This created a whiter flour but was still noticeably darker and more perishable than the refined white flour that's common today.
"Type 80" flour is popular in modern-day France, especially for traditional, whole grain, and rustic breads. The French "T-flour" system classifies flour based on its ash content (i.e., mineral residue after the flour is incinerated). T80 flour has an ash content of 0.80%. Higher numbers indicate less refinement, more bran and germ for darker, more nutritious flour. In contrast, lower numbers indicate a whiter, finer, and less nutritious flour. For example, T45 is a fine pastry flour, while T150 is a coarse, wholemeal flour.